Most prior-art automobiles have faulty suspension systems which tend toward instability on turns. I have discovered that much of this instability is due to the location of the auotmobile roll center axis below the sprung-weight center of gravity, which shifts the load during a turn so as to increase the load on the outside tires and decreases the load on the inside tires, thereby tending to cause the automobile to lift off the inside and roll over the outside. To counteract this fault, many highways have banked turns, but some do not, and on city streets, the turns at intersections cannot be effectively banked because of continuing straight-ahead traffic and because turns are made in both directions. Here, the dangers inherent in conventional design are increased.
Another fault in conventional suspension is the number of angular resolutions of forces. This has a particularly bad effect on the car by providing for large kingpin inclination angles and cambers such that the tires are normally at an inclination to the road rather than at a right angle to it, thereby decreasing tire grip and increasing tire wear.
To counteract some of the effects inherent in conventional designs, spring and shock absorbers are made quite heavy and are usually located at an angle away from vertical rather than truly vertically. In addition to increasing the weight of the vehicle, such designs set up more bending stresses and result in difficulties in access for repair as well as adding to the manufacturing costs. The other conventional frame designs set up more bending stresses.
Another defect in automobile frame designs heretofore has been the poor visibility at the region between the windshield and the front windows and also at other regions. Attempts to add to such visibility have often led to a decrease in the protection afforded by the frame to the driver. The corner posts have been weak and the roof itself has often been very weak in structure, so that crash protection has been ineffectual. Poor visibility has been worsened by the use of curved glass, which also has increased the cost of the vehicle.
Another failing of conventional automobiles has been that the doors have failed to provide adequate crash protection for the occupants.
A further notorious failure in crash protection has been the inability of the bumpers heretofore in use to absorb crash energy.
In conventional designs, the driver has been placed in a relatively unsafe position. Moreover, the structure of the adjacent dashboard and other interior furnishings have increased the likelihood of injuries in the event of a crash.